CAJ | 학술논문

采用量子化学计算和分子动力学(MD)模拟,研究了溶剂化物环四亚甲基四硝胺(HMX)/N,N-二甲基甲酰胺(DMF)的结构和分子间相互作用.对浸渍在DMF溶剂中的β-HMX分子的MD模拟表明,HMX的分子构象已经从β转变为α相.在MP2/6-31G*水平上的理论计算也说明,在DMF溶剂中,α-HMX比β-HMX更稳定.这解释了在HMX/DMF溶剂化物的多晶型中,所有的HMX分子均呈α构象的原因.采用MP2/6-31 G*方法,对α-HMX和DMF分子间可能的同型和异型二聚体进行结构优化.结果表明,组分间存在C—H…O氢键相互作用,并且α-HMX/DMF的稳定化能非常接近α-HMX/αα-HMX,并远远大于DMF二聚体的.这意味着异型分子间力可和同型分子间力竞争.从热力学的观点来看,共结晶过程可能发生.对α-HMX在DMF中的过饱和溶液的MD模拟表明,分子间相互作用对共结晶有利.这些理论研究对理解在HMX的DMF溶液中为什么发生的是共结晶而不是重结晶提供了有价值的信息.
채용양자화학계산화분자동역학(MD)모의,연구료용제화물배사아갑기사초알(HMX)/N,N-이갑기갑선알(DMF)적결구화분자간상호작용.대침지재DMF용제중적β-HMX분자적MD모의표명,HMX적분자구상이경종β전변위α상.재MP2/6-31G*수평상적이론계산야설명,재DMF용제중,α-HMX비β-HMX경은정.저해석료재HMX/DMF용제화물적다정형중,소유적HMX분자균정α구상적원인.채용MP2/6-31 G*방법,대α-HMX화DMF분자간가능적동형화이형이취체진행결구우화.결과표명,조분간존재C—H…O경건상호작용,병차α-HMX/DMF적은정화능비상접근α-HMX/αα-HMX,병원원대우DMF이취체적.저의미착이형분자간력가화동형분자간력경쟁.종열역학적관점래간,공결정과정가능발생.대α-HMX재DMF중적과포화용액적MD모의표명,분자간상호작용대공결정유리.저사이론연구대리해재HMX적DMF용액중위십요발생적시공결정이불시중결정제공료유개치적신식.
The structures and intermolecular interactions for octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX)/N,N-dimethylformamide (DMF) solvate have been investigated through quantum chemistry calculations and molecular dynamics (MD) simulations.MD simulation for a β-HMX molecule immersed in DMF solvent shows that β conformation has been transformed into α form.Theoretical calculations at the MP2/6-31G* level also indicate that the α HMX is more stable thanβ-HMX in DMF solution.This explains why all HMX molecules present α-form in the polymorphic forms of HMX/DMF solvate.Geometrical optimizations at-the level of MP2/6-31G* are performed for all the possible homodimers and heterodimers between α-HMX and DMF. Results reveal that C—H…O hydrogen bond interactions exist between components. Moreover,the stabilization energy of α-HMX/DMF is very close to that of α-HMX/α-HMX and much larger than that of DMF dimer.This means that the heteromeric intermolecular forces can compete with the homomeric intermolecular forces,and co-crystallization is possible to occur from the thermodynamics viewpoint.MD simulation for the supersaturation solution of α-HMX in DMF presents the intermolecular interactions is in favor of co-crystallization.These theoretical investigations provide valuable information for understanding why there occurs co-crystallization other than re-crystallization in DMF solution of HMX.